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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for HCL OneDB™.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in HCL OneDB™ databases.
User-Defined Routines and Data Types Developer's GuideThe HCL OneDB™ User-Defined Routines and Data Types Developer's Guide describes how to define new data types and enable user-defined routines (UDRs) to extend HCL OneDB™.
Create an opaque data type
Creating an opaque data type
Create the internal structure in C

Create the internal structure in C

The internal structure of an opaque data type is a C data structure. For the internal structure, use the C typedefs that the DataBlade® API supplies for those fields whose size might vary by platform. Use of these typedefs, such as mi_integer and mi_float, improves the portability of the opaque data type. For more information about these data types, see the HCL OneDB™ DataBlade API Programmer's Guide.

When you create the internal structure, consider the following impacts of the size of this structure:

The final structure size of the new opaque data type
The alignment in memory of the opaque data type
The method for passing the opaque data type to UDRs

You provide this information when you create the opaque data type with the CREATE OPAQUE TYPE statement.